Display screen or portion thereof with transitional icon



FIG. 1 illustrates a front view of a display screen or a portion thereof having a graphical user interface with a transitional icon showing our new design;

FIG. 2 is a front view of a second image thereof;

FIG. 3 is a front view of a third image thereof;

FIG. 4 is a front view of a fourth image thereof;

FIG. 5 is a front view of a fifth image thereof;

FIG. 6 is a front view of a sixth image thereof; and,

FIG. 7 is a front view of a seventh image thereof.

The appearance of the transitional icon transitions sequentially from the image illustrated in FIG. 1 to the image illustrated in FIG. 7.

The subject matter in this patent includes a process or period in which an image changes into another image. This process or period does not form any part of the claimed design. Further, the broken lines in the drawings showing a display screen or portion thereof do not form any part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with a transitional icon, as shown and described. 